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Physics : Tips
How to Solve any Physics Problem : # Draw a Rough Diagram # List down the knowns and unknowns # Use the best Equation # Solve it Symbolically # Arrive on an Answer Additional Critical Tips : # For Graphs , use only formulae . Substitute different values to obtain the graph . # In case of questions on force or components ; look for al the important forces/components . # If all particles of a body are contributing to a quantity , e.g. Moment of Inertia , Gravitational Field , Electric Field , Magnetic Field ; then find the quantity for a small elemental area and then integrate it between appropriate limits . Measurements # Use dimensional analysis to eliminate options . Try to match dimensions . Scalars and Vectors 1) If in any question , based on any chapter , direction is being asked , then always work with vectors (xi + yj + zk) Kinematics # Preferably make use of Kinematical Equations only . # For 2 dimensiional and three dimensiona motion , break down the motion into 2/3 components and apply kinematic equations to ach independently . (e.g. Projectile Motion ) Force 1) Working with Newton's Laws of Motion i. Select the system ii. Identify the forces iii. Make a free body diagram iv. Choose and write Equations 2) Working with Tension in String : Work, Energy and Power The concepts of Work and Energy can be applied to all MCQs , dealing with momentum , force , velocity , acceleration and height . Friction in Solids and Fluids # For friction , draw the free body diagram and resolve the vectors . Mostly , the free body diagram is standard , so you can learn the resolved forces beforehand . Rotational Motion # For a system of bodies , add up their individual moments of inertia . Electrostatics 1) For repulsive force between two like charges , the closest distance of approach is when Kinetic Energy is equal to Potential Energy . 2) For questions related to Flux and Electric Field Intensity , consider Gauss Theorem . 3) The formulae for E , at diffrent distances from a conductor , circular conductor and at centre of circular conductor is the same as B . Current Electricity # For solving resistances in series and parallel , draw a simpler equivalent diagram of circuit . # When n resistors of Resistance R are connected in series , the total resistance is nR . # When n series of Resistance R are connected in parallel , the total resistance is R/n . # If a wire of resistance R is stretched n (l2/l1) times , The new resistance is n2R # When a complicated symmetric circuit is given for finding resistance , it can be divided into halves to simplify the circuit . # When simplifying a circuit , plot points on the circuit to guide you . # In Wheatstone's network , if the network is balanced , the middle resistance is ignored because no current flows through it . # Whenever , a part of circuit confuses you , remove it and see it's role in the circuit . # The effective resistance for a balanced Wheatstone's Network is R # For equivalent resistances , consider current through each branch . # Use Kirchoff's laws for complicated circuits .